Microwave Kills Germs in Sponges
Microwave Can Sterilize Kitchen Sponges and Plastic Scrubbing Pads, Study Shows
Jan. 24, 2007 -- Your microwave may be a powerful weapon in protecting your
family against disease-causing germs.
A new study shows zapping sponges and plastic scrubbing pads in the
microwave can kill bacteria, such as E. coli, that can cause illness.
"Basically, what we find is that we could knock out most bacteria in two
minutes," says researcher Gabriel Bitton, professor of environmental
engineering at the University of Florida, in a news release. "People often
put their sponges and scrubbers in the dishwasher, but if they really want to
decontaminate them and not just clean them, they should use the
Researchers say disease-causing bacteria and germs from uncooked eggs, meat,
and vegetables often work their way onto countertops and cleaning tools, and
the dampness of sponges, dish cloths, and scrubbers provide an ideal breeding
ground for the bugs.
Microwave Sterilizes Sponges
In the study, published in the Journal of Environmental Health,
researchers evaluated the effects of zapping sponges and plastic scrubbing pads
in the microwave on bacteria and viruses.
The sponges and scrubbing pads were soaked in wastewater containing a
dangerous mix of fecal bacteria, E. coli, and bacterial spores. Bacterial
spores are more difficult to kill.
The results showed that two minutes in the microwave at full power killed or
inactivated more than 99% of all the living germs and the bacterial spores in
the sponges and pads, including E. coli.
After an additional two minutes -- a total of four -- none of the bacterial
Before you zap your sponges in the microwave, researchers offer the
- Microwave only sponges or plastic scrubbers that do not contain steel or
- Make sure the sponge or scrubber is wet, not dry.
- Two minutes should be enough to kill most disease-causing germs.
- Be careful in removing the sponge from the microwave because it will be hot
and should not be handled immediately after zapping.
Bitton recommends that people microwave their sponges according to how often
they cook, with every other day being a good rule of thumb.